KABUL, Aug 14: An explosion killed three soldiers of the US-led coalition while they were on a foot patrol in southern Afghanistan on Thursday, the US military said.

Violence has surged in Afghanistan this year as Taliban militants step up their effort to oust the pro-Western Afghan government and drive out foreign troops through a campaign of guerrilla warfare backed by suicide and roadside bomb attacks.

The US military did not say exactly where in southern Afghanistan the incident took place and did not release the nationality of the soldiers, but the vast majority of coalition troops are American.

Elsewhere, a rocket landed outside the international airport in the Afghan capital on Thursday, but there were no casualties, the Nato-led force said.

The rocket landed in front of the civilian terminal, a spokesman for Nato’s International Security Assistance Force (Isaf) said. Another rocket was also fired, but it was not clear where it landed.

Meanwhile, foreign humanitarian agencies in Afghanistan have restricted staff movements and said they are considering suspending operations in some areas after suspected Taliban militants killed three women aid workers.

The three women worked for US-based International Rescue Committee (IRC) and were shot dead in a car chase on Wednesday as they were travelling through Logar, until this year a relatively peaceful province just south of the capital.

The IRC focuses on providing shelter, water and sanitation to refugees returning to Afghanistan, but has now suspended all its humanitarian aid programmes in the country indefinitely.

Some NGOs have been active at some level in Afghanistan for up to 30 years and are unlikely to pull out of the country. “But what will happen if these kinds of acts continue is that NGOs will be forced to downscale ... reduce the scope of their activities and ultimately the only people who will suffer are the Afghans who rely on the support the NGOs are providing,” said a senior Western aid worker.—Reuters